The program will develop a close-coupled, transcutaneous telemetry system for exchanging electrical power and high bandwidth data across intact skin. Electrical power will be transmitted to the implant by RF inductive coupling and data will be received from the implant by a modulated, low-intensity infrared beam. The telemetry components produced by this program will be ideally suited for neuroprosthetic applications with high channel counts and other medical and biological applications that require high-bandwidth, transcutaneous data links. In Phase I, the feasibility of practical transcutaneous links for data rates up to 40 million bits per second through up to 5 mm of skin was established. In addition, prototype optical assemblies for the external transceiver have been designed and tested. In Phase II, a complete telemetry component set will be completed that includes external telemetry transceivers and implantable VLSl components for processing the data and power signals. These telemetry components will be integrated with 100-channel VLSl amplifier and digitizer modules from a previous SBlR to produce an implantable 100-channel neural recording system with transcutaneous data link for extracellular electrodes.